 \\  &  \multicolumn{2}{c}{Capital investment}    \\       
                    &\multicolumn{1}{c}{Est.}&\multicolumn{1}{c}{S.E.}\\
 \hline  &&\\   
$\Delta$ H.P. of water extraction machines&     371.757&     103.328\\
\addlinespace
$\Delta$ H.P. of hauling machines&     153.167&      49.360\\
\addlinespace
$\Delta$ No. of horses&    2397.790&     955.255\\
  &&\\ R-squared &  \multicolumn{2}{c}{.059} \\ Observations & \multicolumn{2}{c}{8013}         
 && \\ \hline  
